The absorption spectrum of the free SiH2 radical

1968 ◽  
Vol 46 (22) ◽  
pp. 2485-2490 ◽  
Author(s):  
I. Dubois
Keyword(s):  
Absorption Spectrum ◽  
Electronic State ◽  
Vibrational Level ◽  
Visible Region ◽  
Rotational Structure ◽  
Lower State ◽  
High Dispersion ◽  
Bending Vibration ◽  
Lower Electronic State

The absorption spectrum of SiH2 in the visible region has been photographed at high dispersion and the rotational structure of three bands has been analyzed. In the lower electronic state 1A1 the HSiH angle is 92° 5′ and the Si–H distance 1.516 Å, while in the upper state these parameters are 123° and 1.487 Å, respectively. The observed bands correspond to excitation of the bending vibration [Formula: see text] in the upper state. In the lower state, only one excited vibrational level, 010, has been observed, yielding [Formula: see text].

THE ABSORPTION SPECTRUM OF CF2

1967 ◽  
Vol 45 (7) ◽  
pp. 2355-2374 ◽  
Author(s):  
C. Weldon Mathews
Keyword(s):  
Absorption Spectrum ◽  
Electronic State ◽  
Ground State ◽  
Band System ◽  
Electronic States ◽  
Vibrational Structure ◽  
Rotational Structure ◽  
Transition Moment ◽  
High Dispersion ◽  
Parallel Type

The absorption spectrum of CF2 in the 2 500 Å region has been photographed at high dispersion, and the rotational structure of a number of bands has been analyzed. The analysis of the well-resolved subbands establishes that these are perpendicular- rather than parallel-type bands, as previously assigned. Further analysis shows that the upper and lower electronic states are of 1B1 and 1A1symmetries respectively, corresponding to a transition moment that is perpendicular to the plane of the molecule. In the upper electronic state, r0(CF) = 1.32 Å and [Formula: see text], while in the ground state, r0(CF) = 1.300 Å and [Formula: see text]. An investigation of the vibrational structure of the band system has shown that the vibrational numbering in ν2′ must be increased by one unit from earlier assignments, thus placing the 000–000 band near 2 687 Å (37 220 cm−1). A search between 1 300 and 8 500 Å showed two new band systems near 1 350 and 1 500 Å which have been assigned tentatively to the CF2 molecule.

The spectrum and structure of singlet CH 2

1966 ◽  
Vol 295 (1441) ◽  
pp. 107-128 ◽  
Keyword(s):  
Vibrational Level ◽  
Vacuum Ultraviolet ◽  
Lower State ◽  
Absorption Bands ◽  
Bending Vibration ◽  
Near Ultraviolet ◽  
Singlet States ◽  
Lower Electronic State ◽  
Stretching Vibration ◽  
Asymmetric Top

The red absorption bands of CH 2 , previously shown to correspond to a transition between singlet states, have been analysed in detail. In the lower electronic state a 1 A 1 the molecule is a strongly asymmetric top with rotational constants A 000 = 20.14, B 000 = 11.16 and C 000 = 7.06 cm -1 . From these constants a CH distance of 1.11 A and an HCH angle of 102.4° is obtained. In the upper state b 1 B 1 the molecule is nearly linear, having an HCH angle of about 140° and a CH distance of 1.05 A. Most of the observed absorption bands correspond to excitation of the bending vibration v 2 in the upper state (v 2 = 6, 8, ..., 18). In some of them in addition the symmetric stretching vibration v 2 is singly excited. The levels 1, v 2 -4, 0 cause strong perturbations in the levels 0, v 2 , 0 for v 2 = 8, 10, 12, 14. In the lower state only one excited vibrational level 0, 1, 0 has been established which yields v 2 = 1352.6 cm -1. Fragments of some other singlet absorptions in the near ultraviolet and in the vacuum ultraviolet have been observed and are briefly described. The upper state of the near ultraviolet system is probably the predicted 1 A 1 state corresponding to 1 E + in the linear conformation.

Absorption Spectrum of HSiI

1972 ◽  
Vol 50 (6) ◽  
pp. 531-543 ◽  
Author(s):  
J. Billingsley
Keyword(s):  
Absorption Spectrum ◽  
Electronic State ◽  
Isotope Shift ◽  
Flash Photolysis ◽  
Bond Angle ◽  
Rotational Analysis ◽  
Lower Electronic State ◽  
Deuterium Isotope Shift ◽  
Axis Switching

A new absorption spectrum in the region 4600–5600 Å has been discovered in the flash photolysis of silyl iodide, SiH3I. A rotational analysis, together with the observation of a deuterium isotope shift, has shown that the spectrum is due to the HSiI radical.The lower electronic state of HSiI is a 1A′ state with a bond angle of ~103°, and the upper state is 1A″ with angle ~116°. Axis-switching effects, due to the increase in bond angle, cause the appearance of ΔK = 0, ± 2 subbands, in addition to the ordinary ΔK = ± 1 subbands.

THE SPECTRUM AND STRUCTURE OF THE HNO MOLECULE

1958 ◽  
Vol 36 (10) ◽  
pp. 1336-1371 ◽  
Author(s):  
F. W. Dalby
Keyword(s):  
Nitric Oxide ◽  
Absorption Spectrum ◽  
Electronic State ◽  
Flash Photolysis ◽  
Molecular Geometry ◽  
Rotational Analysis ◽  
Experimental Conditions ◽  
Long Wavelength ◽  
Lower Electronic State ◽  
State Formula

The absorption spectrum of HNO in the region 6500–7700 Å has been photographed on a 35-ft grating. The observed spectrum consists of three bands: an intense one at the long-wavelength end of the spectrum and two weaker bands towards shorter wavelengths. All the bands have extensive rotational structure of the perpendicular type. The spectrum was observed after the flash photolysis of nitromethane, nitroethane, isoamyl nitrite, and mixtures of nitric oxide and ammonia. The "lifetime" of the HNO was about 1/10 second under our experimental conditions. The spectrum of DNO has also been photographed. From the constants obtained from the rotational analysis the molecular geometry has been determined. For the lower electronic state[Formula: see text]For the upper electronic state[Formula: see text]The most probable identification of the observed electronic transition is 1A″ ← 1A′.

The D2Σ+ – A2Πi and C2Πr – A2Πi transitions of AlO

1985 ◽  
Vol 63 (9) ◽  
pp. 1162-1172 ◽  
Author(s):  
M. Singh ◽  
M. D. Saksena
Keyword(s):  
High Resolution ◽  
Electronic State ◽  
Rotational Structure ◽  
Rotational Constants ◽  
Vibrational Levels ◽  
Lower Electronic State ◽  
The Common ◽  
First Time

Several bands of the D2Σ+ – A2Πi and C2Πr – A2Πi transitions of AlO have been photographed at high resolution and analyzed for the rotational structure. Rotational structure in the vibrational levels ν = 0, 1, 2, 3, and 4 of the common lower electronic state A2Πi has been investigated for the first time. Rotational perturbations have been observed in the A2Πi state. The equilibrium rotational constants of the A2Πi state are Be = 0.53705 cm−1 and αe = 0.00491 cm−1.

Laser Ionisation Spectroscopy Of Formyl Fluoride

1996 ◽  
Vol 51 (7) ◽  
pp. 809-812
Author(s):  
Reiner P. Schmid ◽  
Harold Jones
Keyword(s):  
Electronic State ◽  
Vibrational Level ◽  
Rotational Structure ◽  
Vibronic Band

A vibronic band of formyl fluoride near 39,511 cm-1 has been observed using multiphoton ionisation spectroscopy. From the analysis of the partially resolved rotational structure, the rotational parameters of the (0, 2, 0, 0, 0, 0) vibrational level of an electronic state near 39,000 cm ~1 have been determined: A = 92.50(1.46) GHz and (B + C)/2 = 11.23(30) GHz. The term value was determined to be 39,510.93(30) cm-1 .

Rotational structure in the NO2 absorption spectrum between 8170 and 8280 Å

1978 ◽  
Vol 56 (11) ◽  
pp. 1502-1512 ◽  
Author(s):  
A. J. Merer ◽  
K-E. J. Hallin
Keyword(s):  
Absorption Spectrum ◽  
Ground State ◽  
Infrared Region ◽  
Zero Order ◽  
Rotational Structure ◽  
High Dispersion ◽  
Detailed Understanding ◽  
Level Densities ◽  
Momentum Coupling

Three parallel-polarized sub-bands, lying in the region 8170–8280 Å in the absorption spectrum of NO2, have been analysed rotationally from high dispersion grating spectra. These sub-bands are assigned as perturbed K = 0, 1, and 4 sub-bands of the [Formula: see text], which appear in absorption because of vibrational momentum coupling with the [Formula: see text], 030–000 band, which lies 137 cm−1 lower in energy. It is shown that in the photographic infrared region of the NO2 spectrum the level densities in the interacting [Formula: see text] and F[Formula: see text] states are sufficiently low that it is possible to identify progressions of vibronically-induced transitions that in zero order would be within the ground state manifold. The implications for a more detailed understanding of the NO2 spectrum are discussed.

The electronic spectra of phenyl radicals

1965 ◽  
Vol 287 (1411) ◽  
pp. 457-470 ◽  
Keyword(s):  
Absorption Spectrum ◽  
Electronic Absorption Spectrum ◽  
Electronic Absorption ◽  
Ground State ◽  
Electronic Spectra ◽  
Flash Photolysis ◽  
Visible Region ◽  
Electronic Configuration ◽  
Vibrational Structure ◽  
Fundamental Frequencies

An electronic absorption spectrum, attributed to phenyl, has been observed in the visible region with origin at 18 908 cm -1 after flash photolysis of benzene and halogenobenzenes. Similar spectra of fluoro, chloro and bromo phenyl are observed after flash photolysis of disubstituted benzenes. The vibrational structure of the phenyl spectrum has been analysed in terms of two fundamental frequencies at 571 and 896 cm -1 which correspond to the e 2 g and a 1 g frequencies of the B 2 u state of benzene. The ground state of phenyl has a π 6 n electronic configuration and the observed transition is interpreted as 2 A 1 → 2 B 1 resulting from a π → n excitation.

scholarly journals SOLVOTHERMAL SYNTHESIS OF BI2WO6 AND ITS PHOTOCATALYTIC ACTIVITY UNDER VISIBLE LIGHT IRRADIATION

2018 ◽  
Vol 54 (4B) ◽  
pp. 42
Author(s):  
Trinh Duy Nguyen
Keyword(s):  
Absorption Spectrum ◽  
Photocatalytic Activity ◽  
Visible Light ◽  
Visible Light Irradiation ◽  
Solvothermal Synthesis ◽  
Solvothermal Method ◽  
Visible Region ◽  
High Photocatalytic Activity ◽  
Light Irradiation ◽  
Different Temperatures

Flower-like Bi2WO6 were successfully synthesized using the solvothermal method at different temperatures and characterized by XRD, FE-SEM, and DRS. We also investigated the photocatalytic activity of Bi2WO6 for the decomposition of rhodamine B under visible light irradiation. From XRD and SEM results, the reaction temperature has significant effects on the morphologies of the samples. From DRS results, Bi2WO6 samples displayed the absorption spectrum up to the visible region and then they showed the high photocatalytic activity under visible light irradiation, as a comparison with TiO2-P25.

OPTICAL SPECTROSCOPY AND NONLINEAR TRANSMITTANCE STUDY OF FULLERENE C60 IN MIXTURES WITH 2-CYCLOOCTYLAMINO-5-NITROPYRIDINE (COANP)

2004 ◽  
Vol 13 (01) ◽  
pp. 113-127 ◽  
Author(s):  
SERGEY S. SARKISOV ◽  
ELENA I. RADOVANOVA ◽  
BURL H. PETERSON ◽  
ALEX LEYDERMAN ◽  
MICHAEL CURLEY ◽  
...  
Keyword(s):  
Optical Properties ◽  
Absorption Spectrum ◽  
Optical Absorption ◽  
Infrared Absorption ◽  
Chemical Bonding ◽  
Infrared Absorption Spectrum ◽  
Visible Region ◽  
Fullerene C60 ◽  
Amino Group

Characterization of the infrared absorption spectrum of the solutions of fullerene C 60 with 2-cyclooctylamino-5-nitropyridine additive has been performed with the focus on possible bonding with the amino-group of the additive. No occurrence of such bonding was found at normal conditions. Also no change of optical absorption in visible region and optical limiting of fullerene due to chemical bonding with the additive was detected. The resulting optical properties of the mixture were simply a sum of the properties of the components for a molar proportion of the additive to fullerene approaching 200:1.

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